Effects of N2O Postdeposition Annealing on Metal-Organic Decomposed CeO2 Gate Oxide Spin-Coated on GaN Substrate

Abstract

Effects of postdeposition annealing (PDA) in N 2 O ambient on metal-organic decomposed CeO 2 films deposited on GaN substrate had been reported. The utilization of N 2 O gas during PDA had successfully suppressed the decomposition of GaN as revealed by x-ray diffraction (XRD). XRD had detected the presence of CeO 2 and a-Ce 2 O 3 phases, wherein the phase transformation of CeO 2 to a-Ce 2 O 3 led to the formation of b-Ga 2 O 3 interfacial layer (IL). Formation of IL comprising of Ga-O and Ga-O-N compounds in CeO 2 /GaN system was verified by dark-field scanning transmission electron microscope image and energy dispersive x-ray line profile, respectively. The metal-oxide-semiconductor characteristics of CeO 2 /GaN structure showed a change of negative to positive effective oxide charge (Q eff ) and increasing interface-trap density (D it ) as a function of PDA temperature. The highest oxide breakdown field demonstrated by 1000 C-annealed sample was correlated with Q eff and D it . A detailed explanation on this correlation as well as current transport mechanism in these oxides has been presented.

Effects of post-deposition annealing ambient on Y2O3 gate deposited on silicon by RF magnetron sputtering

“…The reason that triggered the attainment of a higher intensity of Y 2 Si 2 O 7 peak in this sample was due to the ability of N 2 O gas to perform both oxidation and nitridation processes when compared with N 2 ambient [63][64][65][66]. This was because N 2 O gas could dissociate at high temperature to form N 2 , O 2 , NO, and O [63,65,66]. Despite the fact that N 2 O, N 2 , and FG ambient were capable of performing nitridation process, percentage of N 2 (∼60%) dissociated from N 2 O [66,67] was lower than the percentage of N 2 in pure N 2 and FG ambient.…”

“…TAT mechanism is also known as two-step tunneling mechanism, wherein the applied V g will trigger the injection of electrons to tunnel directly first to the traps located inside the Y 2 O 3 gate oxide and subsequently tunnel from the traps to the conduction band of the Y 2 O 3 gate oxide [85]. The TAT model is given by [64,65,85,86]:…”

Effects of annealing time on the electrical properties of the Y2O3gate on silicon

“…A reduction in the displacement of DV FB with the increase in annealing time may signify the reduction of the trap density in the oxide. This observation is supported through the calculation of Q eff using the following equation [7,23]:…”

Structural and Chemical Studies of Metal–Organic Decomposed LaxCeyOz Thin Film as a Catalytic Oxide on 4H-SiC as a Function of Postdeposition Annealing Time

“…Of these high k gate oxides, cerium oxide (CeO 2 ) has been of particular interest. The CeO 2 has been intensively studied as the gate oxide on various semiconductor substrates, which include Si, , Ge, , 4H-SiC, − and GaN − for metal-oxide-semiconductor (MOS)-based structures. Apart from functioning as a passivation layer in the MOS-based structures, the CeO 2 is also well-known for its catalytic property. , The presence of intrinsic oxygen vacancies in the CeO 2 lattice as well as the redox-ability of the CeO 2 to switch between Ce 4+ and Ce 3+ states has motivated exploration of the CeO 2 . ,, Literature revealed that redox-ability of the CeO 2 is deactivated at high temperature annealing (beyond 800 °C) because active O ions in the CeO 2 lattice are deactivated by inactive O ions .…”